MOFGA's 2009 Pest Reports - Compiled by Eric Sideman, PhD

Late Blight Recap | September 3 | August 12 | July 22 | July 13 | June 25 | June 19 | June 14 | June 1 | May 19   Late Blight Recap - 2009 It all started when the big box stores brought diseased seedlings into the Northeast from down south and sold them to gardeners. With ideal weather conditions for survival, spores spread from these plants and by the end of the summer every corner of the region had late blight. During the season the best organic farmers managed late blight with copper sprays to save their crops and reduce the amount of spores blowing in the wind infecting other plantings. It is important to note that only a few copper products are approved for use on organic crops. Organic growers should contact their certifiers before using any materials to make sure they are allowed. In addition, farmers and gardeners pulled and destroyed or buried diseased plants to reduce the amount of spores blowing in the wind and infecting other plantings. Now that the growing season is coming to an end, there is less to worry about. Late blight only over winters in Maine in living crop tissue, i.e., spores do not survive in soil or crop debris or on stakes or in mulch. The pathogen only survives outdoors here in potato tubers. So, fall clean up is easy for this disease. Allow all plant debris to freeze. Avoid composting or piles that may prevent freezing. Next spring use clean potato seed and scout for potato volunteers. If you do this, and everyone does this, you should be fine and free of late blight. Late Blight Recap | Page 1 of 10 | September 3